Georges Lemaître was a Belgian Roman Catholic priest, honorary prelate, professor of physics and astronomer at the Catholic University of Leuven. He sometimes used the title Abbé or Monseigneur. Lemaître proposed what became known as the Big Bang theory of the origin of the Universe, which he called his 'hypothesis of the primeval atom'.

Lemaître was a pioneer in applying Einstein's theory of general relativity to cosmology. In a 1927 article that preceded Hubble's landmark article by two years, Lemaître derived what became known as Hubble's law and proposed it as a generic phenomenon in relativistic cosmology. Lemaître also estimated the numerical value of the Hubble constant. However, the data used by Lemaître did not allow him to prove that there was an actual linear relation, which Hubble did two years later.

Einstein was skeptical of this paper. When Lemaître approached Einstein at the 1927 Solvay Conference, the latter pointed out that Alexander Friedmann had proposed a similar solution to Einstein's equations in 1922, implying that the radius of the universe increased over time. (Einstein had also criticized Friedmann's calculations, but withdrew his comments.) In 1931, Lemaître published an article in Nature setting out his theory of the "primeval atom."...

Georges Lemaître was a Belgian Roman Catholic priest, honorary prelate, professor of physics and astronomer at the Catholic University of Leuven. He sometimes used the title Abbé or Monseigneur. Lemaître proposed what became known as the Big Bang theory of the origin of the Universe, which he called his 'hypothesis of the primeval atom'.

Lemaître was a pioneer in applying Einstein's theory of general relativity to cosmology. In a 1927 article that preceded Hubble's landmark article by two years, Lemaître derived what became known as Hubble's law and proposed it as a generic phenomenon in relativistic cosmology. Lemaître also estimated the numerical value of the Hubble constant. However, the data used by Lemaître did not allow him to prove that there was an actual linear relation, which Hubble did two years later.

Einstein was skeptical of this paper. When Lemaître approached Einstein at the 1927 Solvay Conference, the latter pointed out that Alexander Friedmann had proposed a similar solution to Einstein's equations in 1922, implying that the radius of the universe increased over time. (Einstein had also criticized Friedmann's calculations, but withdrew his comments.) In 1931, Lemaître published an article in Nature setting out his theory of the "primeval atom."...

The Big Bang theory is the prevailing cosmological model for the earliest known periods of the universe and its subsequent large-scale evolution. It states that the Universe was in a very high density state and then expanded. If the known laws of phy...

Albert Einstein was a German-born theoretical physicist. Einstein developed the theory of relativity, one of the two pillars of modern physics (alongside quantum mechanics). Einstein's work is also known for its influence on the philosophy of science...

Alexander Alexandrovich Friedman or Friedmann was a Russian and Soviet cosmologist and mathematician. He discovered the expanding-universe solution to the general relativity field equations in 1922, which was corroborated by Edwin Hubble's observatio...

Edwin Powell Hubble was an American astronomer who played a crucial role in establishing the field of extragalactic astronomy and is generally regarded as one of the most important observational cosmologists of the 20th century. Hubble is known for s...